Today's network service providers face extraordinary challenges. Traffic levels are rapidly increasing. Both consumers and corporations are demanding higher access rates and staying on the Internet longer while looking for predictable performance and stringent service-level guarantees. This puts direct demands on Internet Service Providers (ISPs) to provide larger capacity and higher speed at their point of presence (POP) locations, preferably without compromising performance.
Just to maintain acceptable performance, service providers are adding support for more users, more traffic, and more transactions, preferably without introducing bottlenecks or compromising network availability. Many network-based businesses transactions are time-critical and typically cannot tolerate undue delay or disruption.
In addition to the challenge of growing traffic levels is the challenge of growing diversity of network technology. Users may access the public infrastructure, for example, over dial-up connections, ISDN links, leased lines, frame relays, ATM virtual circuits. They may use voice-grade modems, cable modems, a variety of xDSL modems, or other modems. Within the infrastructure, a service provider's POP may attach to the core network and to other devices in the POP using, for example, ATM, frame relay, or Ethernet.
Supporting each type of network technology in a traditional manner means that the ISPs typically add separate access servers, access routers, and/or stand alone LAN switches, generally resulting in an increase in cost and management complexities for the ISP.
Increase in user traffic further results in customers dialing-in to the ISP's POP not being guaranteed access at all times due to lack of resources. When the POP is functioning at a maximum capacity, some of the customers are bound to get a busy signal and be refused access.
Accordingly, there is a need for network switch capable of providing fault-tolerant and efficient services that will accommodate the increase in the number and the variety of network traffic. Such a switch should preferably allow ISPs to provide, as one of their value-added services, different access levels to connection requests for prioritizing them when there is a competition for resources.